Method of making disk elements for gate valves



Oct. 3, 1944. J. c. sANDlLANDs 2,359,442

METHOD OF MAKING DISK ELEMENTS FOR GATE VALVES Filed June 14, 1943 2 Sheets-Sheet l Patented Oct. 3, 1944 METHOD OF'MAKING DISK ELEMENTS FOR GATE VALVES f James Caldwell Sandilands, Toronto, Ontario, Canada, assignorto The James Morrison Brass Mfg. C0. Limited, Toronto, Ontario, Canada, a

company of the-'Dominion of Canada Application-June 14, 1943, Serial No. 490,760

3 Claims.

This invention relatesA to gate valves4 and is particularly directed to providing a simplied the disadvantage of increasing the cost of man-V ufacturing the disk as a result of wastage due todefects in the castings or forgings and due to the amount of precision machining work necessary to completethe disk after casting or forging.

It has been found that the disk elements for such valves can be easily and economically manufactured in an easily executed sequence of` operations conducted in, inexpensive production tools from readily available bar stock whereby substantial savings can be effected in the number of operations, and in the labour and tools involved in the manufacture of such elements.`

One of the primary objects of this invention is to provide a method. for making the disk. or gate elements for gate valves whereby the elements are formed from readily available bar stock by an easily executed sequence .of operations involving inexpensive tools.

The method of the present invention includes the steps of cutting a disk of predetermined thickness from the bar stock, drilling two holes transversely through the disk approximate to the periphery and parallel to and between the faces` thereof, the holes being spaced apart equidistant from the centre line of the thickness of the disk, cutting out thel core of metal between the vertical axes of the holes and the periphery to form a V-shaped slot extending parallelV to and between the faces of the said disk and from the periphery to the base of said holes, andv forming a seat finished surface on the sides of said disk, said sides tapering uniformly from the top of said disk to the base thereof.

An understanding of the manner in which the above and other objects of the invention are attained may be had from the following description, reference being made to the accompanying drawings, in which:

Figure 1 is a side elevation in section of a gate valve incorporating a disk or gate element constructed in accordance with the method of the present invention;

Figure 2 is a front elevation partly in section of the valve illustrated in Figure 1;

` DOSE.

Figures 3, 4 and 5 illustrate the stagesof manufacturing the disk;

Figure 6 is end section on the line 6-6 of Figure 7;

Figure '7 is a section on ure 8; and

Figure 8 is a top plan view of the valve disk shown in Figure 7.

Like reference characters refer to like parts throughout the specication and drawings.

With the exception of the disk or gate element, the gate valve illustrated in Figures 1 and.2 is of standard design.

The gatevalve includes, ingeneral, a valve body I4; a bonnet secured to the valve body by the stud bolts 30 and nuts 3Iv; and a gasket 25 serving to seal the jointbetween the valve body and the bonnet.

The upper end of the bonnet I3 terminates in a collar or gland plate 2|) which, by means of the lower yoke stud bolts 28, carries the yoke I2, the upper end of which is secured to a flange 32` by means of the upper yoke stud bolts 21.

A valve stem I'I` extends throughV the yoke and bonnet and into the valve body. A` handwheel I0, secured in place by a locking nut II, is carried on the upper end of the yoke nut 50 whichy engages the upper end of the valve stem andV which extends above the flange 32 for that pur- The lower end of the valve stem is shaped to engage snugly inthe V-shaped s1ot433 formed in the upper part of the valve disk or gate element I5.

The valve body is provided with spaced apart, smooth finished,v tapered seats I6 in which the valve disk is movable in a vertical plane. The sides of the disk are tapered inwardly at an; angle of about 10 from the top to the bottom andv formed with a very smooth tapered finish to correspond with the tapering of the seats I6 and to seat snugly therein.

The upper end of the valve stem is threaded to engage in the internal threads of the yoke. nut 50, whereby, on rotation of the yoke nut by the handwheel I 0, the valve disk I5 is respectively raised or lowered in its seat I6. The valve stem is suitably packed, as indicated, by the gland I9, to prevent the escape of fluid through the assembly.

The method of forming the valve disk or gate element constitutes the principal feature of the present invention and is described in detail hereinafter and illustrated in Figures 3 through 7.

The disk is formed from bar stock, the metal being such as to be substantially resistant to cortheline 'l-l of Figrosion or erosion by the fluid to which it is exposed. Under normal circumstances, it is preferred to use an alloy such as brass or a stainless steel. The bar stock used, of course, is of a diameter only slightly greater than the greatest dimension of the disk desired, to avoid unnecessary Waste of metal.

At the time of cutting a disk of predetermined thickness, the outer perimeter of the disk can be faced to form, in a single operation, a disk of circular section in which the faces are true and the periphery linished. The disk is then drilled to form the holes 35 and 36. The holes are drilled below the top of the disk and spaced apart equidistant from the centre line. These holes are drilled transversely through the disk and parallel to and between the faces thereof.

After drilling the holes 35 and 36, the disk is Vthen put in a lathe and the core of metal between the vertical axes of the holes 35 and 36 is cut out to form, with the holes, the T-shaped slot 33 in which the lower end of the valve stern is received in a snug fitting relationship.

The sides of the disk are tapered uniformly from the top to the base thereof, to fit snugly into the correspondingly tapered seat I6. The tapered sides of the disk are preferably finished with a seat finish.

The lower end of the valve stem I1 is formed with a narrowed neck portion 40 to form an inverted T-shape which nts into the T-shaped slot 33 in a snug fit.

As a specific modification of a disk for a 6 inch gate valve formed in accordance with the present invention, a disk approximately 41/2 inches thick is cut from bar stock about 71/2 inches in diameter. The holes 35 and 36 are drilled 1 inch in diameter, the centres being spaced 1% inches below the periphery and 3%4 inches on each side of the long axis of the thickness of the disk. The core of metal, approximately 13% inches wide between the centres of the holes 35 and 36, is then cut out from the periphery to the base of the holes. At the time of cutting, a slot 42 is cut around the periphery of the disk, the formation of which is incidental to the forming of the T-shaped slot. The slot 42 forms a guide slot which is engaged by the vertical guides 5| formed internally in the valve body. The single machining operation described above, therefore, forms two essential parts of the disk.

At the time of cutting the disk from the bar stock, the faces of the disk can be cut precisely true and the periphery machined to form a surface of exactly circular section, which procedure simplifies the machining operation necessary to impart the proper tapering of the sides and provide a smooth seat finish thereon. The taper of the sides is ordinarily about 10 from the top to the base. The sides of the disk may be indented slightly, as indicated Iby the numeral 43, for ease in raising and lowering the disk out of and into its' position in the seat I6.

I have found it possible to make substantial cations may be made by others skilled in the art to the described steps of the method of the present invention in the light of the teachings herein, without departing from the scope of the invention as defined in the appended claims.

What 1 claim as new and desire to protect by Y' Letters Patent of the United States is:

1. The method of making a disk element for a gate valve which comprises cutting a circular disk of predetermined thickness from bar stock, drilling two holes transversely through the disk approximate to the periphery and parallel to and between the faces thereof, the holes being spaced apart equidistant from the centre line of the disk, cutting out the core of metal between and between the faces thereof, the holes being spaced apart. equidistant from the centre line of the disk, cutting out the core of metal between the vvertical axes of the holes and the periphery to form a T-shaped slot extending parallel to and between the faces of the said disk and from the periphery to the base line of said holes, the formation of said T-shaped slot simultaneously forming a guide slot around the periphery of the disk, and forming a seat finished surface on the sides of said disk,.said sides tapering uniformly from the top of said disk to the base thereof.

3. The method of making a disk element for a gate Valve which comprises cutting a disk of predetermined thickness from bar stock, drilling two holes transversely through the disk approximate-to the periphery, and parallel to and between the faces thereof, the holes being spaced apart equidistant from the centre line of the disk, and cutting out the core of metal between the vertical axes of the holes and the periphery to form a T-shaped'slot extending parallel to and between the faces of the said disks, and from the periphery to the base line of said holes.

JAMES CALDWELL SANDILANDS. 

